Following the use of chemical weapons by Bashar al Assad, who has violated all the red lines in international politics, the US and others have started to discuss a possible military intervention in Syria, but this is mostly because they have concerns about maintaining the legitimacy of the international system.
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Although the use of chemical weapons in Syria has forced the United States (US) administration to take action, it does not seem to make a big difference in the US attitude towards the issue in terms of strategy.
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Having silently stood by in the face of the Assad regimes numerous atrocities over the past two years, all global actors reacted to Assads use of chemical weapons against the civilian population. In this sense, none but Assad himself will be responsible for a possible foreign intervention.
Forget about the intervention against those who betray the norm, the United States does not even adopt a dissuasive strategy in Egypt; therefore, foundations of a period where the use of chemical weapons by authoritarian regimes would be treated as normal from now on have been laid.